/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.cadoc.cqe.logic;



/**
 * A query is a container of predicates that are relations that force
 * the constraints for the result set.
 * 
 * @author aalbert
 */
public interface Pattern {

	/**
	 * Add another constraint
	 * @param predicate
	 */
	public void addPredicate(Predicate<? extends Variable, ? extends Variable> predicate);
	
	/**
	 * Remove a constraint
	 * @param predicate
	 */
	public void removePredicate(Predicate<? extends Variable, ? extends Variable> predicate);
	
	/**
	 * Get an iterable to read out every predicate
	 */
	public Iterable<Predicate<? extends Variable, ? extends Variable>> predicates();
	
	
}
